Post by LAofAnaheim on Jun 28, 2012 7:45:43 GMT -8

I read there's a 39-story tower about to go up at Avenue of the Stars and Santa Monica Blvd next to the Century City Mall - so BH will likely be pointing to that if they haven't already.

Maybe BH's should listen to scientists who can address this question. We do not have the expertise or credibility to speculate why it's ok for a 39 story tower but not a subway station. This is BH problem, they make the layperson make accusations and then turn it into facts. The scientists/seismologists can answer these questions. What happened to a valued education in America?

Post by matthewb on Jun 29, 2012 10:08:39 GMT -8

I read there's a 39-story tower about to go up at Avenue of the Stars and Santa Monica Blvd next to the Century City Mall - so BH will likely be pointing to that if they haven't already.

Maybe BH's should listen to scientists who can address this question. We do not have the expertise or credibility to speculate why it's ok for a 39 story tower but not a subway station. This is BH problem, they make the layperson make accusations and then turn it into facts. The scientists/seismologists can answer these questions. What happened to a valued education in America?

I'm guessing the building is going to be some reasonable number of meters south of the fault. Either way, an underground station is a different beast than a building, and pretty much all of the speculating is being done by people who aren't structural engineers.

Post by gatewaygent on Sept 3, 2012 12:12:46 GMT -8

Too bad the quake activity didn't occur on Santa Monica Bl., by Beverly Hills High School and the golf course. And too bad the ground didn't shift. Although, I'm sure the lawyers would argue that the ground has now settled and it's safe to put the station there.

Post by Gokhan on Sept 6, 2012 23:18:44 GMT -8

The second, magnitude-3.5 earthquake that just happened (and woke me up ten minutes ago) is centered at Crescent Dr and Santa Monica Blvd, at the fault line that goes through the proposed station at Santa Monica Blvd and very close to this proposed station.

Post by Gokhan on Sept 7, 2012 9:20:48 GMT -8

The second, magnitude-3.5 earthquake that just happened (and woke me up ten minutes ago) is centered at Crescent Dr and Santa Monica Blvd, at the fault line that goes through the proposed station at Santa Monica Blvd and very close to this proposed station.

The location has been updated to Wilshire Boulevard and Beverly Drive, with a depth of 0.9 miles. The magnitude has been updated to 3.4.

Therefore, this is not on the fault on Santa Monica Boulevard (that goes through the proposed station) but on the same previously unknown fault as the other earthquake a few days ago.

Now, I will become the devil's advocate.

Since there is fault that goes along Wilshire Boulevard, I think there is a significant chance that there will be a tunnel rupture sometime during the life of the subway, which will be accompanied by a methane leak. I am assuming that they will be installing plenty of methane detectors along the tunnel and they should have adequate time to evacuate the tunnel if this happens. It would probably take months to fix the tunnel and reopen the subway after such an event though.

It's also interesting that the EIR probably didn't study this previously unknown fault that goes right along Wilshire. They might need a supplemental EIR to avoid legal trouble in the future.

Rail obstructionists should accept the fact that at-grade rail deserves as much chance as the at-grade automobile.

Post by gatewaygent on Sept 7, 2012 13:14:40 GMT -8

How long would it take to study the unknown fault? The problem is that now that it's peaking it's ugly head, it has to be dealt with. Otherwise, it will most likely be used as ammunition against the Purple Line. If the route has to be adjusted so that both tunnels are either in the hangingwall or footwall, or so that one tunnel is in the hangingwall and the other in the footwall, so be it. I'm sure this will also alter the decision whether or not to go ahead with a street/mezzanine/center platform configuration (very Metro) or consider a street/nearside platform configuration.

Post by masonite on Sept 7, 2012 14:56:00 GMT -8

How long would it take to study the unknown fault? The problem is that now that it's peaking it's ugly head, it has to be dealt with. Otherwise, it will most likely be used as ammunition against the Purple Line. If the route has to be adjusted so that both tunnels are either in the hangingwall or footwall, or so that one tunnel is in the hangingwall and the other in the footwall, so be it. I'm sure this will also alter the decision whether or not to go ahead with a street/mezzanine/center platform configuration (very Metro) or consider a street/nearside platform configuration.

Geologically, this is very interesting. Geo-politically, this sucks!

They only have to study faults that are capable of producing earthquakes that can cause damage. This may have been on an unknown fault, but the fault may not be able to produce anything stronger than this little quake, which wasn't close to causing any damage. They don't have to study every fault that can do a 3.5 quake, because if so that would be impossible.

Post by Gokhan on Sept 7, 2012 14:56:06 GMT -8

Last night's earthquake's epicenter is only 1000 ft (+/- 700 ft) away from the Wilshire/Rodeo Station. In fact, it could be positioned right under the platform given the uncertainty in the measurement. Monday morning's one was near Wilshire/Doheny. It looks like this previously unknown fault is along Wilshire Blvd, directly aligned under along the tunnels.

Since this is a previously unknown fault, I don't know how long it would take to study the fault and then analyze it if they decided to do so.

The Purple Line is going to be going through a crowded section of L.A., so one would suppose that a mezzanine for ticket machines, gates, other equipment, would be needed as it would be a huge waste to have that at ground level.

Post by gatewaygent on Sept 10, 2012 12:58:34 GMT -8

Thank you James, the linked image of the Muni Church Station conveys what I imagine would be a better station configuration if the fault line were "capable of producing earthquakes that can cause damage." And thank you for that information as well, Masonite.

The ticket machines, elevators, gates, etc. I hadn't accounted for in a nearside platform configuration, drat the luck! Although why couldn't all that be accommodated by extending the platform and creating a pre-boarding, pay, dispatch, etc. zone. The gates would act as the division between the two (2) areas. The potential pitfall of this would be that each side would have to have its own portal for street access.